Bulk carriers transport products in bulk which may be in liquid or solid state.
Considering the bulk carriers which transport solid products such as ore, for example, it is noted that the unloading thereof is quite time-consuming and arduous, besides resulting in the emission of a high quantity of particulates, adversely affecting air quality.
In this sense, the state of the art comprises the process of unloading bulk carriers of solid cargo by way of a cradle disposed at the unloading terminal or port, this cradle being endowed with an overhead crane or mobile tower containing a sucker. The ship docks at the unloading terminal such that the mobile tower and the sucker are positioned over the ship's hold, where the bulk load is deposited.
The mobile tower moves linearly off the ship and along the longitudinal length thereof. During this displacement, the sucker withdraws the solid material from the ship's hold, transports it off the ship and deposits it onto conveyor belt.
The displacement of the mobile tower must be slow and stable, so that the sucker withdraws material steadily along the ship's hold, whereby preventing the vessel's structure from buckling. Accordingly, the unloading operation of carriers is time-consuming, expensive and harmful to the environment, because during suction there occurs the dispersion of particles which remain in suspension in the air.
Another process for unloading bulk carriers loaded with solid cargo by means of equipment found at the unloading terminal and/or port that is known in the state of the art consists of using a gantry or a mobile tower that comprises a dumpster or a “grab”. The boat docks in the unloading terminal in a manner that the mobile tower and the dumpster are positioned above the cargo container of the ship, where the bulk cargo is held.
The mobile tower moves in a linear fashion alongside the boat. During this shift, the dumpster removes the solid bulk from the cargo hold, transports it off the carrier and deposits it on a conveyor belt system.
The displacement of the mobile tower should be stable, so that the dumpster may collect from the cargo hold in a constant fashion. This makes the unloading process for bulk carriers expensive and time consuming.